Continuous press

ABSTRACT

A continuous press comprising a tubular apertured screen and a cylindrical sleeve disposed coaxially within the screen, the sleeve being held against rotation relative to the screen. One or more annular or helicoidal ripples are repeatedly formed on and around the outer surface of the sleeve. The pressure applied to the wet pulp entering the press and the compressive action of the rippling sleeve outwardly towards the screen combine to move the wet pulp lengthwise of the screen while progressively compressing the pulp to squeeze the juice therefrom.

United States Patent [191 Johnson [111 3,831,516 Aug. 27, 1974 CONTINUOUS PRESS Inventor: Wallace J. S. Johnson, Berkeley,

Calif.

Assignee: Upright, Inc., Berkeley, Calif.

Filed: Oct. 12, 1972 Appl. No.: 297,000

Related US. Application Data Continuation-impart of Ser. No. 192,545, Oct. 26, 1971, abandoned.

[52] US. Cl 100/116, 100/110, 100/117, 100/145, 100/211 Int. Cl 1330b 9/06, B30b 9/12, B20b 5/02 Field of Search l00/37,'1l7, 116, 126, 100/127, 128,129, 145, 211, 121,118, 110, 113, 114, 157, 144, 145; 162/401, 56; 210/304, 5, 433

References Cited UNITED STATES PATENTS 10/1951 Ketchum 100/110X 2,593,292 4/ 1952 Gaugler. 100/211 X 2,912,923 ll/1959 Jung 100/117 3,624,729 11/1971 Hoover 100/211 FOREIGN PATENTS OR APPLICATIONS 1,155,760 3/1961 Germany 100/211 Primary ExaminerPeter Feldman Attorney, Agent, or FirmHill, Moore, Weissenberger, Lempio & Strabala [57] ABSTRACT A continuous press comprising a tubular apertured screen and a cylindrical sleeve disposed coaxially within the screen, the sleeve being held against rotation relative to the screen. One or more annular or helicoidal ripples are repeatedly formed on and around the outer surface of the sleeve. The pressure applied to the'wet pulp entering the press and the compressive action of the rippling sleeve outwardly towards the screen combine to move the wet pulp lengthwise of the screen while progressively compressing the pulp to squeeze the juice therefrom.

31 Claims, 14 Drawing Figures CONTINUOUS PRESS I RELATED APPLICATION This application is a continuation-in-part of my prior application Ser. No. 192,545, filed on Oct. 26, 1971, entitled Continuous Press, and now abandoned BACKGROUND OF THE INVENTION In making white wine the must (crushed grapes) is pressed to extract the juice therefrom. In making red wine the pomace (wet skins and seeds left in the fermenter after the fermented wine is removed) is pressed to extract the remaining wine therefrom. Batch pressing, i.e., where a single batch of must or pomace is placed in a container and then pressed to extract the juice, has been practiced since Biblical days. Batch pressing has an advantage in that the degree of pressing may be relatively easily controlled so that the seeds and skins are not crushed to such an extent that they will release bitter juices therefrom. Such method, however, is limited in capacity since it is inherently slow. The pressing of a single batch must be completed, and the compacted dry cake of seeds and skins removed from the container before a new batch may be processed.

Continuous wine presses have been developed wherein the must is continuously introduced into one end of the press, with the juice being squeezed from the seeds and skins while in the press and with the dry seed and skin cake being continuously removed from the other end of the press. To the best of applicants knowledge. all presently used continuous wine presses are of the screw type wherein a continuously rotating screw pushes the crushed grapes along a cylindrical screen,

pressing the grapes against the screen so that the juice will drain through the holes or slots in the screen. Since the screw is in direct contact with the crushed grapes, it will inherently subject the material to both rotational and lengthwise movement relative to the screen. As a consequence there is no way to prevent the seeds and skins from being abraded across the edges of the screen apertures. Such abrasion releases the relatively bitter juices from the seeds and skins and lowers the quality of the pressed juice.

Thus, batch pressing will produce high-quality juice but at a relatively low rate of production. Continuous pressing will produce juice at a higher rate but at a lower quality.

The principal object of the invention is to provide a press having the advantages of both, i.e., the high production rate of a continuous press and the high quality of a batch press.

SUMMARY OF THE INVENTION The principle of operation of the present invention is derived from the peristaltic phenomenon. Peristalsis in nature takes place by means of a porous tube being squeezed inwardly on a semi-liquid mass in such a slowly rippling manner that the mass is pushed along within the tube at the same time that the liquid oozes out through the pores of the tube. By the time the mass reaches the end of the tube it is practically dry. As such, the overall results of solid compaction and liquid extraction are thesame as those desired in a wine press or indeed in any other press wherein liquids are to be separated from solids, such as for other fruits and vegetables, sludge, manure, paper fiber, textile fiber, and so forth.

Natural peristalsis is inherently slow and is limited in capacity by the diameter of the porous tube. To achieve a greater capacity, the peristalsis principle has been turned inside out for application in the present in vention. Thus, instead of squeezing a porous tube inwardly to propel and compress the mass inside, the present invention uses a rigid porous tube and a flexible tubular inner member inside of the porous tube, the semi-liquid mass being in the annular space between the porous tube and tubular inner member. The squeezing action takes place within the flexible tubular inner member, causing wave-like annular or helicoidal ripples repeatedly along the length of the inner member, which ripples in conjunction with the force of the entering mass, cause the mass to move along the length of the porous tube, with the liquid being forced to ooze out through the pores of the outer tube. With this arrangement, the capacity of the press is significantly greater, since the annular space between the inner and outer members provides a much greater capacity for the same thickness of material being acted upon.

In a grape press, the outer porous tube is preferably in the form of a cylindrical bar screen, with longitudinal bars spaced from one another to form lengthwise slots of a size slightly smaller then the diameter of a grape seed. The material moves longitudinally through the press, with no rotative movement being imparted thereto. Therefore, the seeds, skins and other solids will slide through the press in the same direction as the slots and there will be no abrasion of the seeds and skins by the slots as would occur if the seeds and skins were forced to move across the slots.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings forming a part of this application, and in which like parts are designated by like reference numerals throughout the same,

FIG. I is an elevational sectional view of a first form of ,a press constructed in accordance with the invention;

FIG. 2 is a sectional view of the press, taken on line 22 of FIG. 1;

FIG. 3 is a sectional view of the press, taken on line 3-3 of FIG. 1;

FIG. 4 is a sectional detail, in enlarged scale, of the flexible sleeve used in the press of FIG. 1;

FIG. 5 is an elevational detail view of the flexible sleeve used in the press of FIG. 1;

FIG. 6 is an elevational sectional view of a second form of press constructed in accordance with the invention;

FIG. 7 is a sectional detail illustrating the manner inwhich the press of FIG. 6 is assembled;

FIGS. 8, 9, 10 and 11 are illustrative details of the screen and flexible sleeve of the press of FIG. 6, showing the manner in which ripples are generated along the sleeve; 7

FIGS. 12a and 12b are an elevational sectional view of a third form of press constructed in accordance with the invention, FIG. 12a showing the press at one stage of its operation and FIG. 12b showing the press at another stage of operation;

FIG. 13 is a sectional detail, on an enlarged scale, of the compression members of the press of FIGS. 12a and 12b.

DESCRIPTION OF PREFERRED EMBODIMENTS Embodiment of FIGS. 1-5

The press illustrated in FIGS. l-5 comprises a vertical column member having an imperforate upper section 1] and an apertured lower section 12. An inlet opening 13 is provided into the upper section to charge the press, as needed, with must to be pressed. A source 14 of CO gas under pressure is connected through pipe 15 to the interior of the upper section of the press.

The apertured lower section comprises a bar screen 16 made up of a plurality of elongated bars 17, square or rectangular in cross section, arranged vertically to form a cylinder, and spaced from one another circumferentially to form a plurality of vertical slots 18, the spacing between the inner surfaces of the bars being slightly less than the diameter of a grape seed. The bars 17 are held in fixed position by annular retaining rings 19 surrounding the bar screen.

Secured to the lower end of the bar screen 16 is an annular collector pan 20 provided with one or more drain conduits 21. If desired, one or more annular collector pans 22 may be secured to the outer surface of the bar screen at one or more levels between the top and bottom thereof. Each such collector pan is provided with one or more drain conduits 23.

An annular imperforate casing 24 is secured to collector pan 20 and extends upwardly above the bar screen, the upper end of the casing being secured to the upper column section 11, the casing being sealed to the press so that air outside of the press is prevented from coming into contact with the juice being squeezed through the bar screen. The column member 10 is supported by legs 26 on platform 27.

An upwardly pointed cone member 28 is mounted within the upper column section, coaxially therewith, the cone being mounted in place by three pipe sections 29, 30 and 31 extending through the upper column section. Attached to the lower skirt 32 of the cone in sealed relation thereto is the upper end of flexible sleeve 33, the sleeve being firmly secured to the cone skirt by retaining ring 34 to hold the sleeve against lengthwise or rotational movement relative to the bar screen. Similarly, the lower end 35 of sleeve 33 is firmly secured by retaining ring 36 to the periphery of the annular support member 37, which is fixedly mounted to platform 27. Support member 37 is provided with a drain pipe 58 for a purpose to be described hereinafter.

The flexible sleeve 33 is preferably formed of three elastomer plies 41, 42 and 43, the center ply 42 having relatively inelastic cords 44 embedded therein and running the length only thereof. Such cords will prevent lengthwise stretching, i.e., from top to bottom, of the sleeve while allowing circumferential stretching thereof.

A polished metal screw 45 is disposed inside the flexible sleeve 33 coaxially with the bar screen 16, the screw having a continuous helical thread 46 therein running from top to bottom thereof. As seen in FIG. 1, the thread 46 is preferably tapered, with the radius of the thread crest 47 being constant and the radius of the thread root 48 increasing downwardly, so that the helicoidal space between the thread valley and the bar screen becomes progressively smaller in a downward direction.

The screw 45 is hollow, the upper end being closed by plate 49. An annular baffle 51 is disposed inside the screw with an inlet pipe 52 being connected to the bottom of the baffle and extending upwardly through plate 49 to the rotary coupling 53 on the inner end of pipe support 29. Plate 49 has a plurality of discharge orifices 54 connecting to the annular space between baffle 51 and the inner surface of screw 45.

The sleeve 33 has an inner radius sufficiently small relative to the least radius of the thread root 48 so that when the screw is inside the sleeve, the sleeve will be stretched over the screw and will pull into the thread valley to conform to the shape of the thread. If the sleeve radius is too great, the sleeve will not take the shape of the screw; if too small, there will be excessive friction between the sleeve and screw.

Screw 45 is driven by motor 55 which acts on the screw through a gear reducer 56 and drive shaft 57.

The pressdescribed above may be operated for a continuous form of batch pressing or for fully continuous pressing, as desired. For example, in the pressing of a single batch, air or CO gas under pressure can be introduced into the cone through pipe support 30, causing the upper end of the flexible sleeve to expand outwardly into contact with the inner surface of the upper column section 11, as indicated by the dotted lines in FIG. 1. Must is then charged into the top of the column through the inlet opening 13 and allowed to settle therein. The free-run juice will settle to the bottom, and

the seeds and skins (typically about 10 percent of the must) will float to the top. After settling, the gas pressure in the cone is reduced, allowing the sleeve 33 to contract so that the free-run juice may drain down therepast and out through the bar screen slots into the free-run juice collector pan 22.

As the liquid level in the upper column portion lowers, the solid matter in the must will come into contact with the upper surface of cone 28, and will slide down the inclined surface thereof and be guided to the annular spacebetween the flexible sleeve and the column member. If there tends to be some bridging of this annular space by the solids, CO gas under pressure may be introduced through pipe 15 to help force the material downwardly.

When the solids in the must have descended to the bar screen level, motor 55 is turned on to drive screw 45 at a slow speed of rotation. Water, or other lubricating fluid, will have been previously admitted through pipe support 29, down through pipe 52 and up through the cooling jacket formed by baflle 51 into the interior of the cone, filling the cone to the level of the pipe support 31 which serves as an overflow or discharge conduit. Some of the water above the screw will be drawn downwardly between the screw and the flexible sleeve by the screw rotation to provide lubrication and some cooling, this water draining out through drain pipe 58.

As the screw rotates in the sleeve, it will generate a continuous series of annular ripples in the sleeve which move downwardly, forcing the semi-fluid mass between the sleeve and the bar screen downwardly. Since the sleeve is held against rotation at the top and bottom thereof, the rotation of the screw will not be imparted to the mass and only a downward force will act on the mass. Thus, the seeds and skins will be moved only along the length of the bars 17 and the slots therebetween and will not be moved across the slots which would cause detrimental abrasion of the solids.

The mass in the upper portion of the helicoidal space is subjected to a relatively gentle pressing action and the juice passing through the bar screen to the upper collector pan 22 is of free-run juice quality. The exact height of pan 22 will depend on the vintners decision as to how much pressing may occur before the juice may no longer be considered to be of free-run quality. As the mass continues to move downwardly under the slow rippling action of the sleeve, it will become progressively more compacted, with the press-run juice being squeezed through the bar screen and flowing downwardly into the lower, press-run juice, collector pan 20. If desired, an additional collector pan could be used at a level between pans and 22 to separate the press-run juice into high and low-quality press-run uice.

By the time the mass reaches the bottom of the sleeve, it will be a relatively dry cake of seeds and skins, which cake will be extruded from the press through the annular space between the lower ends of the sleeve 33 and the column member 10.

After the batch has been processed, the above operations would be repeated.

For fully continuous operation, must is simply added through the upper inlet opening 13, as desired, while the press is in operation.

If desired, the gas pressure in the cone may be set at a desired value to inflate the sleeve and maintain the fluid level in the upper column section at a desired height. Thus, if the level were higher, the weight of the liquid would be sufficient to cause it to squeeze past the inflated sleeve and enter the press portion of the device. lt may also be desirable to maintain a gas pressure in the cone to cause partial inflation of the sleeve on the screw to provide a more gentle pressing action while at the same time decreasing the friction between the screw and the sleeve.

By virtue of the gentle, non-rotational action of the press, a larger percentage of the juice will be produced as high-quality free-run juice. Similarly, even the pressrun juice will be of higher quality because of the elimination of seed and skin abrasion by the non-rotational action.

Merely by way of illustration, a prototype of the abovedescribed press has been designed with a 16 inch inside diameter of the upper settling tank portion and of the bar screen, the screen being made of 5/16 inch square bars. The flexible sleeve 33 is three-ply, 50 durometer, with the inner ply being tire cord. Tire cord,

as used in the tire industry, is an unvulcanized rubber sheethaving a plurality of parallel threads embedded therein. The sleeve 33 uses such tire cord, with the embedded threads running the length of the sleeve; the sleeve 33 is, of course, vulcanized after the forming thereof. The screw thread 46 has 10 flights with a 2 inch pitch, and the annular space between the sleeve and bar screen decreases from 1 inch at the top to 1/4 inch at the bottom, resulting in a 4/ l compression ratio. A 14 inch diameter sleeve is used, the expansion thereof by air, or on the screw, to a 16 inch diameter being only 14 percent. Preferably there is a maximum clearance of 1/16 inch between the helically expanded sleeve and the bar screen. A larger clearance minimizes the peristaltic action. Too small a clearance may result in binding or crushing of seeds, although seed-crushing will be minimized because of the resilience of the sleeve 33. However, a' 1/8 inch clearance or larger may prove desirable, perhaps with a somewhat higher screw speed, in order to provide a genetle pressing action.

Typically, crushed must comprises about 50 percent free juice, 40 percent pulp and 10 percent seeds and skins. A 4/1 compression of the pulp, seeds and skins will thus result in a relatively dry seed-and-skin cake, the cake having enough moisture therein so that it can be easily extruded from the press. The motor and gear reducer drive the screw at 3.5 r.p.m. Since there are 10 flights, the material entering the top of the sleeve will be subjected to pressing for approximately 3 minutes before it is extruded from the press. Approximately 1 ton of crushed must may be pressed in one hour with continuous operation.

As described above, the pulp in the helicoidal space between the sleeve and the screen will be progressively compacted since the pulp is squeezed into aneverdecreasing space. Such compaction will occur even if all of the material being pressed moves lengthwise through the press as a mass and at the same rate of movement as the rate of ripple movement. However, for many materials there will .be some dragging action between the material and the sleeve or screen, or both. In such case, as the ripples move along the sleeve, much of the material will be moved through the press by and with the ripples, but some of the material will be ridden over by the crests of the ripples and will be compacted between the ripple crests and the screen. The compacted material will be then urged through the press bythe material in the next ripple. The latter compaction, between the thread crests and the screen, does not require the use of a tapered screw, and can occur if the helicoidal space between the sleeve and screen were uniform. In order to obtain compaction in the helicoidal space and also between the ripple crests and the screen, a screw with a tapered thread should be used, as shown in the preferred embodiment. If only the latter compaction were desired, the screw could be made with a uniform thread, producing ripples of uniform volume along the sleeve.

With the preferred vertical orientation of the press, the press may be easily charged with material to be pressed, the material will be evenly distributed to the annular space between the rippling sleeve and the screen, and the juice will drain out by gravity from the full circumference of the screen. Gravity also will aid in causing the material to be moved downwardly by the I rippling sleeve. However, the major impetus for the compacting and conveying action of the press comes from the power applied to the rotating screw. Asa consequence, the pressing action is not restricted to a vertical orientation but can result if the screw, sleeve and screen are vertical, horizontal or any other desired angle, as long as the rippling sleeve is able to move the particular material being operated upon through the press.

Embodiment of FIGS. 6-11 tion 66, a lower bar screen section 67, and a base section 68 supporting the press on platform 69. An annular casing 70 surrounds the bar screen section to collect free-run juice in the upper compartment 71 and pressrun juice in the lower compartment 72. A pan 73 is secured to platform 69 below the column member to receive the compressed cake discharged from the press, the cake being removed from pan 73 by screw 74.

An upwardly pointed cone member 75 is mounted within the upper column section 66 by pipe sections 76 extending through the upper column section. Attached to the lower skirt 77 of the cone in sealed relation thereto is the upper end of flexible sleeve 78, the sleeve 77 extending downwardly the full height of the bar screen 67.

The interior of the flexible sleeve 78 is divided into four transverse, fluidly separated compartments 81, 82, 83 and 84 as follows. Four pipes, three of which, 85, 86 and 87, are shown, extend through base section 68 and project upwardly within sleeve 78. The pipes are spaced 90 from each other with the fourth pipe 88 being diametrically opposite to pipe 86. The pipes are externally threaded throughout their height, and nuts 89 threaded thereon support and hold the transverse partition plates 90, 91, 92, 93 and 94 in place. As best seen in FIG. 7, partition plate 94 comprises upper and lower parallel sections 940 and 94b, beveled at their edges to form an annular groove. In assembling partition plate 94, nuts 89 would be threaded into place at a common height on each of the pipes 85.88. Plate section 941; would be dropped in place on nuts 89, within sleeve 78. A retainer ring 95 would be put in place around sleeve 78 and plate section 94a would then be dropped into place on the pipes 85-88. Nuts 89 would then be threaded down the pipes and tightened, drawing the plate sections together and causing the retainer ring 95 to hold the sleeve 78 firmly and sealingly within the annular groove formed by the plate sections. The lower partition plates would have been assembled in the same way. A perforated cylinder 96 extends from the upper partition plate 94 upwardly to cone 75.

Pipe 85 has openings 85a to compartment 84, and to that compartment alone. Similarly, pipes 86, 87 and 88 have openings which connect them to compartments 83, 82 and 81 respectively. Pipes 85-88 extend to cylinders 97, 98, 99 and 100 of a four-piston pump 101, each of which cylinders has a piston therein driven 90 out of phase with the piston in the next cylinder.

Compartments 81-84, pipes 85-88 and the pistons of pump 101 are all charged with hydraulic fluid, e.g., water or oil. FIG. 8 illustrates the condition of the press when the pistons of pump 101 are in the positions shown in FIG. 6. The piston in cylinder 97 has moved all the way to the left, forcing fluid into compartment 84 and bulging out of the resilient sleeve 78 into engagement with the bar screen 67. The piston in cylinder 98 is moving to the left, forcing fluid into compartment 83, bulging the sleeve outwardly in the direction shown by the arrow on FIG. 8. The piston in cylinder 99 has moved all of the way to the right, which has exhausted fluid from compartment 82 so that the sleeve 78 has returned to its original unbulged conditionQThe piston in cylinder 100 is moving to the right, exhausting fluid from chamber 81 so that the sleeve is returning in the direction of the arrow from a fully bulged position.

FIGS. 9. l and 11 are similar, and illustrate the sleeve positions at 90 intervals in a cycle of operation of pump 101. As, for example, in FIG. 8 the upper portion of sleeve 78 has been bulged completely out to the bar screen. A quarter of a cycle later, FIG. 9, the bulge in the upper portion of the sleeve has been reduced. A quarter of a cycle later, FIG. 10, the upper portion of the sleeve has returned to its original unbulged position, before again bulging outwardly as in FIG. 11. Also, as will be seen in FIGS. 8-11, during a complete cycle of pump operation, the full bulge will progress downwardly along the sleeve.

In operation, the upper portion of the column member will be charged with must, with the free-run juice flowing through the bar screen into collector chamber 71 and the pulp passing down into the annular space between the flexible sleeve 78 and the bar screen. The slowly rotating pump 101 will cause a sequential ripple of annular bulges in the flexible sleeve which provides a steady kneading of the pulp, squeezing the juice therefrom, which passes through the bar screen to collector compartment 72, and resulting in an increasingly dry cake as the pulp progresses downwardly through the press. The dry cake is extruded from the lower end of the press and falls into pan 73 for disposal by screw 74.

Fluid under pressure may be exerted through pipes 76 into the interior of cone 75, which fluid can pass through the perforations in cylinder 96 to bulge the upper end of sleeve 78 and towards the imperforate upper column section 66 for the reasons described in connection with the previous embodiment.

Embodiment of FIGS. 12a, 12b and 13 The press illustrated in FIGS. 12a, 12b and 13 again comprises a vertical column member 110, substantially as described in connection with the previous two embodiments, the column member having an imperforate upper section 111 and a lower bar screen section 112 and the casing for collecting free and press-run juice. Again, a cone member 113 is disposed coaxially in the column member, and a flexible sleeve 114 is secured at its upper end to the cone member.

The ripple-producing mechanism inside the flexible sleeve comprises, in this embodiment, a plurality of steel rings 116 bonded alternately to rubber, or other suitable elastomer, rings 117, stacked upon each other, with the flexible sleeve being stretched over the outer periphery of the rings. The lowermost and uppennost rubber ring are engaged by plates 118 and 119 which have a central opening through which piston shaft 120 extends. The upper end of the piston shaft has a bearing nut 121 threaded thereon and in engagement with plate 119. The lower end of piston shaft 120 is provided with a piston head 122 thereon disposed in cylinder 123 which is mounted on the bottom of plate 118. Cylinder 123 is .supported on base section 124 of the column member 110 by suitable struts 125. The interior of cylinder 123 is connected by pipe 126 to a hydraulic pump 127. A flexible hose 128 extends up through plate 118 and interiorally of the stack of steel and rubber rings to a fitting 129 through plate 119 so that fluid under pressure may be introduced through hose 128 into the space below cone 113 and out through the apertures 130 in cylinder 131 to bulge the upper end of sleeve 1 14 outwardly to the upper imperforate column section 111 if and when desired, as illustrated in FIG. 12b.

In operation, the upper portion of the column member is charged with must, with the free-run juice passing out through the upper portion of the bar screen and the pulp passing down cone 113 by gravity or gas pressure or both to the annular space between the sleeve 114 and the bar screen 112.

Pump 127, which is operated at a slow rate of speed, will begin to pump hydraulic fluid into cylinder 123 to force piston shaft 120 downwardly, which in turn causes the rubber rings 117 to be compressed between the steel rings. The outer peripheries of the rubber rings will be squeezed or bulged outwardly, stretching the encompassing flexible sleeve 114 outwardly to form a series of outwardly projecting annular ripple crests 129 on the outer surface of the sleeve, as illustrated in FIGS. 12b and 13. The steel rings 116 will of course be unaffected by the compression and will not expand the sleeve, thus forming a plurality of annularpockets 130 between the sleeve and bar screen. It will be noted from a comparison of FIGS. 12a and 12b that as the rubber rings are compressed, the horizontal centerline of each ring will be moved downwardly. Thus, the compression action will both squeeze the juice outwardly and will move the remaining pulp downwardly. The uppermost rings will move downwardly a greater distance in each cycle of operation than the lower rings, thereby increasing the concentration of the cake as the pulp moves downwardly.

After the piston shaft reaches its lowermost position and moves back upwardly, the rubber rings return to their uncompressed position and the annular space between the sleeve and screen refills with must from above. The action is then repeated. The dry cake extruded from the bottom of the press can then fall into a pan and be disposed of by screen conveyor, as described in connection with the last embodiment.

If desired, the uppermost rubber ring may be made of lower durometer material than the others. In such case, the uppermost ring will be squeezed outwardly, before and to a greater extent than the rest, thereby providing a sealing action against the bar screen to prevent upward movement of the pulp past the uppermost ring during the compression phase of the operation.

In addition, by using rubber rings of successively higher durometer as they are layered downwardly, the

peristaltic effect can be amplified.

As shown in FIGS. 12a, 12b and 13, the flexible sleeve extends from cone 113 to the bottom plate 118,

surrounding the elastomer rings 117. If .desired, the flexible sleeve 114 can instead extend from cone 113 only to upper plate 119 and be secured thereto. In such case the outer surfaces of the elastomer rings 117 and steel rings 116 would be in direct contact with the material passing through the press and such surfaces would serve as a continuation of the flexible sleeve, functioning in the same manner to form a series of outwardly projecting annular ripple crests when the rings are compressed.

Have thus described my invention, 1 claim:

1. A continuous press comprising:

a. an elongated apertured tube,

b. a flexible annular sleeve disposed coaxially in said tube, I

c. means to hold said sleeve against rotation in said tube,

d. means for repeatedly expanding portions of said sleeve outwardly towards said screen to form repeated ripples in the outer surface of and completely around said sleeve.

2. A continuous press as set forth in claim 1 wherein said tube has a plurality of narrow continuous slots therethrough extending lengthwise of said tube adjacent said sleeve.

3. A continuous press as set forth in claim 1 wherein said means d) comprises:

a helical screw disposed coaxially in said sleeve, said sleeve being stretched over said screw,

means to rotate said screw within said sleeve.

4. A continuous press as set forth in claim 3 and further including means to inject fluid under pressure between said screw and said sleeve.

5. A continuous press as set forth in claim 3, wherein said sleeve includes a plurality of relatively unstretchable cords therein running the length of said sleeve.

6. A continuous press as set forth in claim 3, wherein the helicoidal space between the valley of the screw thread and the tube is progressively smaller from one end of the screw to the other.

7. A continuous press as set forth in claim 1 wherein said means (d) comprises:

means forming the interior of said sleeve into a plurality of fluidly independent'transverse chambers,

means for introducing and exhausting fluid under pressure into and from each of said chambers.

8. A continuous press as set forth in claim 1 wherein said means (d) comprises:

a stack of ring members, alternately of incompressible material and elastomeric material, disposed coaxially within said sleeve, said sleeve being stretched over said stack,

means for repeatedly compressing said stack to expand the outer surfaces of the elastomer ring members outwardly.

9. A continuous press as set forth in claim 8 wherein the elastomeric ring members progressively increase in hardness.

10. A continuous press comprising:

a. a tubular member having an imperforate section and an apertured cylindrical section,

b. means for introducing semi-fluid material to be pressed into the imperforate section of said tubular member,

c. an imperforate guide member disposed in said tubular member coaxially therewith,

d. a flexible sleeve secured at one end to said guide member, said sleeve extending inside and along said apertured cylindrical section of said tubular member,

e. means securing said sleeve against rotation relative to said tubular member,

f. means surrounding said apertured cylindrical section to collect juice passing through said apertured section,

g. means for repeatedly expanding portions of said sleeve outwardly towards said tubular member to form repeated ripples in the outer surface of and completely around said sleeve.

11. A continuous press as set forth in claim 10 wherein said apertured cylindrical section comprises a plurality of elongated bars spaced from one another around the circumference of said section to form a plurality of continuous slots therebetween adjacent said sleeve.

12. A continuous press as set forth in claim 10 wherein said guide member is disposed in the imperforate section and is spaced from said apertured section such that a portion of said sleeve may expand into circumferential contact with said imperforate section and further including means to inject fluid under pressure into said sleeve portion.

13. A continuous press as set forth in claim wherein said means (f) comprises a plurality of collector members along said apertured section, each collector member collecting juice passing through a lengthwise portion only of said apertured cylindrical section.

14. A continuous press as set forth in claim 10 wherein said means (g) comprises:

a helical screw disposed coaxially in said sleeve, said sleeve being stretched over said screw,

means to rotate said screw within said sleeve.

15. A continuous press as set forth in claim 14 and further including means to inject fluid under pressure between said screw and said sleeve.

16. A continuous press as set forth in claim 14, wherein said sleeve includes a plurality of relatively unstretchable cords therein running the length of said sleeve.

17. A continuous press as set forth in claim 14, wherein the helicoidal space between the valley of the screw thread and the apertured cylindrical section is progressively smaller in the direction away from said guide member.

18. A continuous press as set forth in claim 10 wherein said means (g) comprises:

means forming the interior of said sleeve into a plurality of fluidly independent transverse chambers,

means for introducing and exhausting fluid under pressure into and from each of said chambers.

19. A continuous press as set forth in claim 10 wherein said means (g) comprises:

a stack of ring members, alternately of incompressible material and elastomeric material, disposed coaxially within said sleeve, said sleeve being stretched over said stack,

means for repeatedly compressing said stack to expand the outer surfaces of the elastomeric ring members outwardly.

20. A continuous press as set forth in claim 19 wherein the elastomeric ring members progressively increase in hardness.

21. A continuous press comprising:

a. a vertical column member having an imperforate upper section and an apertured cylindrical lower section,

b. means for introducing semi-fluid material to be pressed into the upper section of said column member,

c. an upwardly extending conical guide member disposed in said column member coaxially therewith,

d. a flexible sleeve secured to the lower end of said conical member, said sleeve extending downwardly inside and along said apertured cylindrical section of said column member,

e. means securing said sleeve against rotation relative to said tubular member,

f. means surrounding said apertured cylindrical section to collect juice passing through said apertured section and to shield said juice from air,

g. means for repeatedly expanding portions of said sleeve outwardly towards said apertured cylindrical section to form ripples in the outer surface of said sleeve, which ripples extend completely around said sleeve and progress lengthwise relative to said apertured cylindrical section.

22. A continuous press as set forth in claim 21 wherein said apertured cylindrical section comprises a plurality of elongated bars spaced from one another around the circumference of said section to form a plurality of continuous slots therebetween adjacent said sleeve.

23. A continuous press as set forth in claim 21 wherein the lower end of said conical member is disposed in the imperforate upper section and at a sufficient height above said apertured lower section such that the upper end of said sleeve may expand into circumferential contact with said imperforate section and further including means to inject fluid under pressure into the upper end of said sleeve.

24. A continuous press as set forth in claim 21 and further including an imperforate collector member disposed in said shield means (f) and circumferentially surrounding said apertured cylindrical section at a height substantially above the lower end of said shield means to collect juice passing through the upper portion only of said apertured cylindrical section.

25. A continuous press as set forth in claim 21 wherein said means (g) comprises:

a helical screw disposed coaxially in said sleeve, said sleeve being stretched over said screw,

means to rotate said screw within said sleeve.

26. A continuous press as set forth in claim 25 and further including means to inject fluid under pressure between said screw and said sleeve.

27. A continuous press as set forth in claim 25, wherein said sleeve includes a plurality of relatively unstretchable cords therein running the length of said sleeve.

28. A continuous press as set forth in claim 25, wherein the helicoidal space between the valley of the screw thread and the apertured cylindrical section is progressively smaller in a downward direction.

29. A continuous press as set forth in claim 21 wherein said means (g) comprises:

means forming the interior of said sleeve into a plurality of fluidly independent transverse chambers,

increase in hardness downwardly. 

1. A continuous press comprising: a. an elongated apertured tube, b. a flexible annular sleeve disposed coaxially in said tube, c. means to hold said sleeve against rotation in said tube, d. means for repeatedly expanding portions of said sleeve outwardly towards said screen to form repeated ripples in the outer surface of and completely around said sleeve.
 2. A continuous press as set forth in claim 1 wherein said tube has a plurality of narrow continuous slots therethrough extending lengthwise of said tube adjacent said sleeve.
 3. A continuous press as set forth in claim 1 wherein said means (d) comprises: a helical scRew disposed coaxially in said sleeve, said sleeve being stretched over said screw, means to rotate said screw within said sleeve.
 4. A continuous press as set forth in claim 3 and further including means to inject fluid under pressure between said screw and said sleeve.
 5. A continuous press as set forth in claim 3, wherein said sleeve includes a plurality of relatively unstretchable cords therein running the length of said sleeve.
 6. A continuous press as set forth in claim 3, wherein the helicoidal space between the valley of the screw thread and the tube is progressively smaller from one end of the screw to the other.
 7. A continuous press as set forth in claim 1 wherein said means (d) comprises: means forming the interior of said sleeve into a plurality of fluidly independent transverse chambers, means for introducing and exhausting fluid under pressure into and from each of said chambers.
 8. A continuous press as set forth in claim 1 wherein said means (d) comprises: a stack of ring members, alternately of incompressible material and elastomeric material, disposed coaxially within said sleeve, said sleeve being stretched over said stack, means for repeatedly compressing said stack to expand the outer surfaces of the elastomer ring members outwardly.
 9. A continuous press as set forth in claim 8 wherein the elastomeric ring members progressively increase in hardness.
 10. A continuous press comprising: a. a tubular member having an imperforate section and an apertured cylindrical section, b. means for introducing semi-fluid material to be pressed into the imperforate section of said tubular member, c. an imperforate guide member disposed in said tubular member coaxially therewith, d. a flexible sleeve secured at one end to said guide member, said sleeve extending inside and along said apertured cylindrical section of said tubular member, e. means securing said sleeve against rotation relative to said tubular member, f. means surrounding said apertured cylindrical section to collect juice passing through said apertured section, g. means for repeatedly expanding portions of said sleeve outwardly towards said tubular member to form repeated ripples in the outer surface of and completely around said sleeve.
 11. A continuous press as set forth in claim 10 wherein said apertured cylindrical section comprises a plurality of elongated bars spaced from one another around the circumference of said section to form a plurality of continuous slots therebetween adjacent said sleeve.
 12. A continuous press as set forth in claim 10 wherein said guide member is disposed in the imperforate section and is spaced from said apertured section such that a portion of said sleeve may expand into circumferential contact with said imperforate section and further including means to inject fluid under pressure into said sleeve portion.
 13. A continuous press as set forth in claim 10 wherein said means (f) comprises a plurality of collector members along said apertured section, each collector member collecting juice passing through a lengthwise portion only of said apertured cylindrical section.
 14. A continuous press as set forth in claim 10 wherein said means (g) comprises: a helical screw disposed coaxially in said sleeve, said sleeve being stretched over said screw, means to rotate said screw within said sleeve.
 15. A continuous press as set forth in claim 14 and further including means to inject fluid under pressure between said screw and said sleeve.
 16. A continuous press as set forth in claim 14, wherein said sleeve includes a plurality of relatively unstretchable cords therein running the length of said sleeve.
 17. A continuous press as set forth in claim 14, wherein the helicoidal space between the valley of the screw thread and the apertured cylindrical section is progressively smaller in the direction away from said guide member.
 18. A continuous press as set forth in Claim 10 wherein said means (g) comprises: means forming the interior of said sleeve into a plurality of fluidly independent transverse chambers, means for introducing and exhausting fluid under pressure into and from each of said chambers.
 19. A continuous press as set forth in claim 10 wherein said means (g) comprises: a stack of ring members, alternately of incompressible material and elastomeric material, disposed coaxially within said sleeve, said sleeve being stretched over said stack, means for repeatedly compressing said stack to expand the outer surfaces of the elastomeric ring members outwardly.
 20. A continuous press as set forth in claim 19 wherein the elastomeric ring members progressively increase in hardness.
 21. A continuous press comprising: a. a vertical column member having an imperforate upper section and an apertured cylindrical lower section, b. means for introducing semi-fluid material to be pressed into the upper section of said column member, c. an upwardly extending conical guide member disposed in said column member coaxially therewith, d. a flexible sleeve secured to the lower end of said conical member, said sleeve extending downwardly inside and along said apertured cylindrical section of said column member, e. means securing said sleeve against rotation relative to said tubular member, f. means surrounding said apertured cylindrical section to collect juice passing through said apertured section and to shield said juice from air, g. means for repeatedly expanding portions of said sleeve outwardly towards said apertured cylindrical section to form ripples in the outer surface of said sleeve, which ripples extend completely around said sleeve and progress lengthwise relative to said apertured cylindrical section.
 22. A continuous press as set forth in claim 21 wherein said apertured cylindrical section comprises a plurality of elongated bars spaced from one another around the circumference of said section to form a plurality of continuous slots therebetween adjacent said sleeve.
 23. A continuous press as set forth in claim 21 wherein the lower end of said conical member is disposed in the imperforate upper section and at a sufficient height above said apertured lower section such that the upper end of said sleeve may expand into circumferential contact with said imperforate section and further including means to inject fluid under pressure into the upper end of said sleeve.
 24. A continuous press as set forth in claim 21 and further including an imperforate collector member disposed in said shield means (f) and circumferentially surrounding said apertured cylindrical section at a height substantially above the lower end of said shield means to collect juice passing through the upper portion only of said apertured cylindrical section.
 25. A continuous press as set forth in claim 21 wherein said means (g) comprises: a helical screw disposed coaxially in said sleeve, said sleeve being stretched over said screw, means to rotate said screw within said sleeve.
 26. A continuous press as set forth in claim 25 and further including means to inject fluid under pressure between said screw and said sleeve.
 27. A continuous press as set forth in claim 25, wherein said sleeve includes a plurality of relatively unstretchable cords therein running the length of said sleeve.
 28. A continuous press as set forth in claim 25, wherein the helicoidal space between the valley of the screw thread and the apertured cylindrical section is progressively smaller in a downward direction.
 29. A continuous press as set forth in claim 21 wherein said means (g) comprises: means forming the interior of said sleeve into a plurality of fluidly independent transverse chambers, means for introducing and exhausting fluid under pressure into and from each of said chambers.
 30. A continuous press as set forth in claim 21 wherein said means (g) comprises: a stack of ring meMbers, alternately of incompressible material and elastomeric material, disposed coaxially within said sleeve, said sleeve being stretched over said stack, means for repeatedly compressing said stack to expand the outer surfaces of the elastomeric ring members outwardly.
 31. A continuous press as set forth in claim 30 wherein the elastomeric ring members progressively increase in hardness downwardly. 